| Official Name: | Waterloo, West Virginia |
| Pushpin Map: | West Virginia#USA |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | West Virginia |
| Subdivision Type2: | County |
| Subdivision Name2: | Mason |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 564 |
| Coordinates: | 38.7308°N -81.9344°W |
| Area Code: | 304 & 681 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 1549980 |
Waterloo is an unincorporated community in Mason County, West Virginia, United States. Waterloo is located on County Route 31, 2miles southeast of Leon.[1]